Antenna used to transmit microwave data, such as cellular voice communications, streaming video, Internet data and the like, must be aligned, or boresighted, to a relatively high degree of accuracy in order to achieve optimum broadcast reception and transmission. Typically, microwave antennae must be aligned to within about 5 degrees or so. In order to accomplish this alignment, surveyors provide precise ground coordinates and geodesic reference points for a physical location of each antenna. This information in turn is given to a technician, who then uses an iterative process to align the antennae and permanently or semi-permanently fix each antenna in place for best reception and transmission of signals from a distant antenna. In some instances, the technician must travel one or more times between two antennae being aligned, which may be 50-60 miles or further apart, in order to precisely align the antennae. The process is expensive, as surveyors are required to provide the ground coordinates of each antenna, and the technician must not only have some electronics training and experience, but must also be trained to climb towers and the like where the antenna dishes are located.
Known prior art includes U.S. Pat. No. 6,897,828, to Boucher, which uses two GPS satellite dishes spaced apart a known distance along an arm mounted to the antenna to be aligned, the arm extending in a direction of radio waves emitted by the antenna. A hand-held controller allows communication between the two GPS dishes. The controller is configured to calculate an azimuth the arm is pointed toward, which allows a technician to manually rotate the arm with the antenna to be aligned attached thereto, to point toward a predetermined azimuth.
One disadvantage of this system is that the azimuth from one antenna to the next must already be known to a relatively high degree of precision. Also, the technician is still required to manually perform a fine alignment of the antennae. Further, the obtained azimuth from the two GPS dishes depends on the accuracy of the GPS system providing a location of each dish, which can be problematic. As such, the system of Boucher only reliably provides what can be considered a coarse alignment. Further yet, only one antenna at a time can be aligned.
Another patent to Boucher, U.S. Pat. No. 7,501,993, teaches an antenna alignment system wherein one or two reference targets are fixed to an antenna to be pointed along a known azimuth direction. One or two GPS receiver dishes are mounted to reference tools, i.e. a theodolite or the like, with the two receiver dishes used to locate two points, P1 and P2, which are located a known distance apart. The reference positions are also calibrated with respect to a reference azimuth and to each other relative to geometric North. Calculations are then performed to determine an azimuth axis of the antenna, which allows the antenna to be aligned along the azimuth axis.
Problems with this system are that it requires an elaborate setup wherein the positions P1 and P2, which are not on the structure where the antenna to be aligned is located, must be determined. Also, the tower or other structure must be climbed once in order to prepare the antenna for alignment, and climbed one or more times to align the antenna. As with Boucher's first patent, the predetermined azimuth to the next antenna must be relatively precisely known in advance in order to align the two antennas. Also, like Boucher's first patent, only one antenna at a time may be aligned.
According to the following specification, Applicants provide an automated antenna alignment system that can simultaneously align two antennae, the process resulting in highly accurate alignments at ranges of up to 50 miles or more.